Soil order

Vertisol

Soil very clayey, with clays that swell when wet and contract when dry: when dry it opens wide and deep cracks, and when wet the layers slide against each other leaving slickensides.

What it means for farming

Fertile and with a lot of water retained, but difficult: they become waterlogged, when wet they become sticky and difficult to work with, and when dry they crack. They ask for tillage at the right time. They are the typical soil of much of Entre Ríos.

Vertisoles on the maps

Udert

Vertisol humid climate: cracks open for a short time each year.

Acuert

Vertisol with excess water and redox depletions near the surface.

Xerert

Vertisol Mediterranean climate.

The definitions are a plain-language summary of the USDA Keys to Soil Taxonomy. The formal definition includes thickness, color and percentage thresholds that are left out here.

Sources